Extinction is the idea that some plants and animals that once inhabited the planet are no longer found in today’s world. It has only been in the last 200 years that scientists have accepted the idea of extinction. In the seventeenth and eighteenth centuries, although scientists knew about fossils being the remains of plants and animals, the religious doctrines did not include the possibilities of organisms becoming extinct. They believed that the fossil animals and plants had not yet been discovered in such places as deep in the Amazon jungle or any other unexplored part of the globe.